Ladder.



No. 786,658. PATENTED APR. 4, 1905.

- B. L, MERRILL.

LADDER.

APPLICATION FILED DEOJO, 1903.

. I 6 gluwmfoz aftonwqd L Patented April 4, 190's.

UNITED STATES PATENT QEETcE.

BUEL L. MERRILL, OF LITCHFIELD, MAiNE.

LADDER.

SPECIFICATION forming part of Letters latent No. 786,658, dated April 4, 1905.

Application filed Decembef 10, 1903. Serial No. 184,631.

T at whom it may concern.-

Be it known that 1, Beer. L. MERRILL, a citizen of the United States, residing at Litchfield, in the county of Kennebec and State of Maine, have invented certain new and useful Improvements in Ladders; and i do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention has particular reference to extension-ladders, and especially to such as are designed, for assuming the form of a step-lad der; and the object in view is the provision of means in combination with such extensionladder for locking the parts thereof in their given relations.

With this and further objects in view the invention consists in combination, with a plurality cf ladder-sections, of means connecting said sections together and permitting longitudinal movement thereof with respect to each other and a cam carried by one of said sections for engaging the other of said sections for locking the same against movement.

It further consists in certain other novel constructions, combinations, and arrangements of parts, as will he hereinafter fully described and claimed. i

In the acconmanying drawings, Figure 1 represents a perspective view of aladder embodying the features of the present invention and illustrated as positioned for forming a step-ladder. Fig. 2 represents a similar View of the same extended. Fig. 3 represents an enlarged detail perspective view of the looking mechanism.

Referring to the drawings by numerals, 1 indicates a lower, 2 an intermediate, and 3 an upper, section. To the sides of the lower section 1 are secured depending hooks 4t 4:, adapted to engage the sides of the section 2, said sides.

of section 2 being spaced apart a distance slightly less than the distance apart of the 5 sides of section 1, whereby the section 2 is adapted to slide longitudinally between the sides of section 1, supported and guided by the hooks 4. The lower ends of the sides of section 2 carry hooks 5 5 bent outwardly, up-

0 wardly, and about the respective sides of the lower section 1, whereby the lower ends of the sides of section 2 are guided in their iongitudinal movement; The sides of section 2 on their upper edges are formed with lockreceiving notches 6 6, preferably semicircular in form and adapted to receive locking-cams 7 7, carried by a rotatably-mounted rung 8, forming part of section 1. The cam 7 at one end of rung 8 is formed with a fiat-faced projecting dog 9, adapted in operation to engage the flat upper edge of its respective side of section for locking its cam against rotation, and thereby preventing longitudinal movement of the said section. Both of the cams T are fixed to the rung 8, and the cam opposite that carrying dog 9 is provided with an operating-handie 10,formcd with a flat under surface adapted to engage the upper edge of the corresponding side of section 2 for limiting the given cam against rotation, and thus .ock-

ing the said side against longitudinal movement when said cam is within one of the notches 6. Section 3 is pi votally connected to straps 11 11, said straps being fixed to section 2 near the upper end thereof, and a hook 12 is employed for locking the upper rung of section 2 to the lower rung of section 3 for retaining the said sections in proper position when extended. A hook 13 is hung from one of the rungs of section 2 and is adapted to engage one of the rungs of section 8 when said section 3 is lowered for forming an inclined support for sections 1 and In operation, when it is desired to cause the sections to assume the extended. condition illustrated in Fig. 2, section 2 is moved longitudi nally of section 1 as far as desired and the cams 7 are permitted to drop within a set of notches 6, whereby said sections are locked in their given relation. The section 3 is next raised on its pivots, and hook 12 caused to engage a rung of section 2 and a rung of section 3. The ladder is then in condition for use. When it is desired to change the ladder from this position to a folded-up position, it is only necessary to remove the hook 12 and rotate the cams 7 by grasping handle and pulling the same outwardly. As soon as the cams 7 have moved out of the notches 6 the section 2 is free to he slid longitudinally of section 1, and the sections may be locked in a closed position by turning the cams 7 into the uppermost notches of section 2. The section 3 may be swung upon its pivots into contact with section 2, and the parts will be in their most compact form. From this form the ladder may be changed to the step type by simply swinging the section3 outwardly to a plane at an acute angle to the longitudinal plane of the other sections and securing said section 3 in position by dropping the hook 13 over one of the rungs oi the same.

Having thus fully described my invention, what 1 claim as new, and desire to secure by Letters Patent, is

1. 111 a device of the class described, the combination with slidably-connected laddersections, of a cam pivotally carried by one of said sections, and lying contiguous to one edge of the other section, said second-mentioned section being formed with a notch in that edge next to said cam, of a size and shape designed to receive the cam, and means to limit the rotation of said cam in one direction.

2. In a device of the class described, the combination with a plurality of slidably-con nected ladder-sections, one of said sections being formed with a notch, oi a cam pivotally carried by the other of said sections and adapted to lit within said notch, and a laterally-projecting dog extending from said cam and adapted to engage the notch-section for preventing rotation 01'' the earn.

3. in a device oi. the class described, the combination with a plurality of slidablyconnected ladder-sections, one of said sections be ing formed with a notch, of a cam pivotally carried by the other of said sections and adapted to fit within said notch, and means for preventing rotation of said cam in one direction while within the notch.

at. In a device of the class described, the combination with a plurality of slidably-connected ladder-sections, one of said sections be ing formed with a notch in its upper surface, of a cam pivotally carried by the other of said sections and positioned for swinging in avertical plane parallel to the longitudinal axis of said ladder-sections and adapted to be swung within the said notch for locking the sections against longitudinal movement with respect to each other, nd means for preventing rotation of said cam in one direction while within the notch.

5. In a device of the class described, the combination with a plurality of slidably-com nected ladder-sections, of a retatably-mounted rung carried by one of said sections, a cam, projecting laterally from said rung and positioned for swinging in a vertical plane parallel to the longitudinal axis of said ladder-sections when said rung is rotated, the other laddersection having one of its side rails lying in. the path of movement of said cam.

In testimony whereof I hereunto afiix my signature in presence of two witnesses.

BUEL L. MERRILL.

Witnesses:

O. B. GLAsoN, MABEL Conn. 

